[U-Boot] [xHCI] Controller failure with USB 3.0 hub

[Bin Meng]

Hi Marek,

On Sat, May 19, 2018 at 7:54 PM, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Marek,
>
> On Sat, May 19, 2018 at 7:30 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
>> On 05/19/2018 01:09 PM, Bin Meng wrote:
>>> Hi Marek,
>>
>> Hi,
>>
>>> On Sat, May 19, 2018 at 9:03 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
>>>> Hello Bin,
>>>>
>>>> I noticed a potential bug in the U-Boot xHCI implementation. I observe
>>>> this one Renesas RCar Gen3 platform.
>>>>
>>>> If I plug a USB 3.0 hub into the root port, I see the following error:
>>>>   ERROR: Configure Endpoint command returned completion code 5.
>>>> If I plug a USB 3.0 stick into the root port, I do not get the error and
>>>> the stick is correctly detected.
>>>>
>>>> Example with the USB 3.0 hub:
>>>>
>>>> => usb reset
>>>> resetting USB...
>>>> USB0:   Register 2000120 NbrPorts 2
>>>> Starting the controller
>>>> USB XHCI 1.00
>>>> USB1:   USB EHCI 1.10
>>>> USB2:   USB EHCI 1.10
>>>> USB3:   USB EHCI 1.10
>>>> ******** HERE ********
>>>> scanning bus 0 for devices... ERROR: Configure Endpoint command returned
>>>> completion code 5.
>>>
>>> Completion code 5 means TRB parameter error, guess the Renesas xHC has
>>> some checks on the TRB.
>>
>> Do you have xhci spec chapter reference/number for me too ? :)
>>
>
> I was looking at xhci spec 1.1 chapter 6.4.5 TRB Completion Codes. I
> don't have Renesas xHC manual to cross check.
>
>>> Can you try the following patch to see if it makes any difference?
>>>
>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>>> index 3adb002..eec3f64 100644
>>> --- a/drivers/usb/host/xhci.c
>>> +++ b/drivers/usb/host/xhci.c
>>> @@ -1453,6 +1453,8 @@ static int xhci_update_hub_device(struct udevice
>>> *dev, struct usb_device *udev)
>>>         if (udev->speed == USB_SPEED_HIGH)
>>>                 slot_ctx->tt_info |= cpu_to_le32(TT_THINK_TIME(think_time));
>>>
>>> +       slot_ctx->dev_state = 0;
>>> +
>>>         return xhci_configure_endpoints(udev, false);
>>>  }
>>
>> Doesn't make any difference, sorry.
>>
>
> Too bad. Then I don't have any obvious clue so far. The completion
> code 5 is a helpful sign from xHC to the software that something was
> wrong in the TRB. Per the xHCI spec, dev_state needs to be cleared. It
> was working with the x86 xHC though. Changing
> xhci_configure_endpoints(udev, false) to
> xhci_configure_endpoints(udev, true) is not correct as the Evaluate
> Context command is not used with configure the hub attributes.

To continue debugging this, could you print out the slot context
contents (slot_ctx->*) before calling xhci_configure_endpoints(udev,
false)?

Regards,
Bin